1. Field of the Invention
The present invention relates to a surveillance system especially for automatically watching and chasing an intruder and the like.
2. Description of the Related Art
Conventionally, there has been used a watching system for watching an intruder and the like. The conventional surveillance system is available for watching unqualified people and other intruders intruding into a special room that does not permit people with any permission from entering. One typical example of the surveillance system 700 is shown in FIG. 17 as comprising a camera unit 710, a display unit 730 for displaying an image taken by the camera unit 710, and a control unit 740 for controlling the operation of the camera unit 710 in response to operation commands inputted therein.
Description will now be made on how the image taken by the camera unit 710 is displayed on the screen of the display unit 730.
When the camera unit 710 is operated to take an image to be displayed on the screen of the display unit 730, the camera unit 710 is firstly driven by the control unit 740 to transform the image into an image signal outputted to a signal transmitting cable 701. The image signal thus outputted to the signal transmitting cable 701 is then transmitted to a system unit 720 before being inputted to the display unit 730.
The image signal is then transformed into an image to be displayed on the screen of the display unit 730.
The following description is directed to the operation of having the camera unit 710 operated in compliance with the operation commands inputted into the control unit 740.
In order to have the camera unit 710 operated by the operation commands of the control unit 740 to photograph an image, the control unit 740 is operated to receive the operation commands respectively indicative of the photographing directions, magnifications and the like inputted by an operator while he or she is watching the screen of the display unit 730. The control unit 740 inputted with the operation commands is then operated to transform the operation commands into a command signal to be transmitted to a signal transmitting cable 703. The command signal thus transmitted to the signal transmitting cable 703 is then inputted to the system unit 720 where the command signal is then transformed into a drive signal to drive the camera unit 710 to be outputted to the camera unit 710 by way of the signal transmitting cable 701. The camera unit 710 thus received the drive signal from the system unit 720 is at this time operated to change the photographing directions, magnifications and the like into new ones.
It is thus to be noted from the previously mentioned description that the camera unit 710 is operated in compliance with the operation commands inputted into the control unit 740.
As will be seen from the above, there has been described only one camera unit 710 provided in combination with the system unit 720, the display unit 730, the control unit 740 in the conventional surveillance system for the purpose of simplifying the description and assisting in understanding about the whole operation of the surveillance system. In reality, such a conventional surveillance system 800, however, is as shown in FIG. 18 to comprise a plurality of camera units 810, a system unit 820, a plurality of display units 830, and a plurality of control units 840. The conventional surveillance system 800 thus constructed allows an operator to selectively operate those control units 840 to input to control units 840 operation commands indicative of selecting one or more camera units 810 and one or more display units 830. This leads to the fact that the operator can select one or more control units 840 not only to have the image displayed on the screen of one or more display units 830 in accordance with the image taken by one or more selected camera units 810 but to operate the camera units 810 under the operation states optioned by the operator.
Here, the conventional surveillance system is generally known as being constructed to automatically detect and chase moving objects such as intruders and other objects to be taken by the camera units.
The conventional surveillance system encounters such a problem that it is impossible to decide which one of the objects is to be chased by the camera or cameras if there is a plurality of objects on the screen of the display unit.